Grinding machine



' June 17,1941.

B, c. SPURLING GRINDING "MACHINE Filed Sept. 11, 1940 5 Sheets-Sheet 1June 17, .1941. B. c. SPURLING 7 2,246,023

GRINDING MACHINE 7 Filed Sept. 11, 1940 5 Sheets-Sheet 2 June 17, 1941.c, S URUN 2,246,023

GRINDING MACHINE I Filed Sept. 11, 1940 5 Sheets-Sheet 3 a Q. v v i lfin M r i M. W fix. g, m

June 17, 1941. c, SPURUNG 2,246,023

GRI-NDING' MACHINE Filed Sept. 11, 1940 5 Sheets-Sheet 4 I l v Juie 17,1941. P R NG 2,246,023

GRINDING MACHINE Filed Sept. 11, 1940 5 Sheets-Sheet 5 Patented June 17,1941 leaf T I Gamnnic. Manama Bertram Charles Spurling, deceased, lateof Leicester, England, by Mildred Ann Spurling, administratrix,Leicester, England, assignor to The Bentley Engineering Company Limited,Leicester, England, a British company Application September 11, 1940,Serial No. 356,388 In Great Britain December 24, 1938 goi. 51-109) 13Claims.

This application corresponds to the application of Bertram CharlesSpurling and The Bentley Engineering Company Limited, Serial No.-

ular outline can be ground with accuracy. It

is well known to grind profiles in blanks by causing a carriage whichholds a blank to move in a suitable path determined by a pattern whileholding the blank against a grinding wheel.

According to the present invention a grinding machine comprises incombination a grinding wheel and a carriage somounted as to be free tomove in any direction parallel to an imaginary plane of reference whichis itself parallel to the grinding wheel axis but not away from saidplane, a support for attaching a master pattern to the carriage, asupport on the carriage for holding a blank tobe ground in line with themaster pattern in a direction normal to the said plane parallel to whichthe carriage is movable and presenting it to the grinding wheel, and astationary guide in line with the grinding wheel in a direction normalto the said plane to engage the profile of the master pattern, so thatthe carriage can be moved parallel to the said plane to cause thepattern to traverse the guide and thus cause the grinding wheel toreproduce the pattern on the blank.

Other features of the invention will be more clearly understood from thefollowing description of a preferred example of the invention taken inconjunction with the accompanying drawings, in which Figure 1 is aperspective view of the apparatus according to the invention;

Figure 2 is a plan of the mechanism illustrated in Figure 1, a portionbeing broken away for the sake of clearness, and is a section on theline 2-2 of Figure 3;

Figure 3 is an elevation of the apparatus shown in Figure 2, parts beingshown in section;

Figure tv is a section on the line 44 of Figure 2;

Figure 5 is a section on the line 55 of Figure 2;

Figures 6 and 7 show in elevation a truing device used in conjunctionwith the grinding wheel, and

Figure 8 is a plan of the device shown in Figure 7.

Like reference numerals indicate like parts in the several figures ofthe drawings.

The grinding wheel I t is mounted to rotate about a horizontal axis in afixed grinding head indicated as a whole by the reference numeral On ahorizontal plane, at a level.

II in Figure 1. below that of the grinding wheel, is a fixed table I2whichsupports the carriage l3 already mentioned. Between the carriageand the table l2 are ball, roller or other anti-friction devicesenabling the carriage to be movable with freedom in all directions inits own plane. In the example shown these antifriction devices comprisea series of balls I4 mounted between outer race *rings I5 and inner racerings, not shown, which latter are secured to the under side of thecarriage l3. The carriage can therefore move in any direction parallelto an imaginary plane oi, reference the direction of which is determinedby the table I2 so as to be parallel to the grinding wheel axis.

' Adjustable on the carriage is a support for a master pattern It andthis support conveniently takes the form of a shallow channelled memberH which constitutes the upper member of what is virtually a compoundslide rest. The master pattern can be held in the channel by means ofbolts IE or the like and the member I! is formed on its under side witha key or guide H! which is guided in a corresponding groove in acompanion member 20 lying beneath it. A lead screw 2! rotatably mountedat 22 in an overhanging portion 23 of the member I1 is so. mounted thatwhile it is free to rotate it is in-.

capable of endwise movement relatively to the part 23. The lead screwitself engages within a correspondingly threaded recess in the slidemember 20 so that by rotation of the lead screw 2! the member I! can beadjusted towards and away from the grinding wheel. The slide member 20is formed with side flanges engaging above a slide or guide portion 24formed on the base of the carriage I 3. The flanges on the member 20 andthe guide portion 24 are formed I to guide movement of the slide 20 in adirection at right angles to the movement of slide I9, and the positionof slide 2!] on the guide 24 is controlled by means of lead screws 25situated on each side of the member 20. The lead screws 25 are threadedinto correspondingly threaded orifices extending laterally throughbearing brackets 26 formed integralwith and uprising from the basemember I3, and the inner ends of the lead screws 25 abut against thesides of slide member 20.

The brackets 26 support a strong square-sectioned cross member 21,portions of which are cylindrically ground to be carried in bearingsleeves 28 mounted in the upper portions or brackets 26. The bearingsleeves 23 are oppositely tapered as clearly shown in Figure 3 and areheld in position by means of nuts 29 each of which is threaded on to theinner end of its sleeve 28 so as to bear against the adjacent surface ofbracket 26. The central portion of the cross member 21 is speciallyshaped as shown clearly in the drawings to afford a rearwardly'extending bracket I29 from which rise upstanding lugs 36. Mounted on thebracket I29 in any preferred manner or formed integral with it is acradle 3| of semi-cylindrical form and in this cradle is carried atwo-part work-holder, the lower member 32 of which has its outer surfaceshaped to conform to the inner surface of the cradle 3|. The outermember 33 of the workholder is mounted in the lower member 32 so as tobe capable of sliding in guides therein towards and away from thegrinding wheel and if a curved workpiece is to be ground the extremitiesof the upper work-holder are curved or relieved as at 34. In order tose'cure the two-parts of the work-holder in their adjusted positions, aset screw 35 is screwthreaded into the part 32 and its shank passesthrough an arcuate slot in the cradle 3| to permit the part 32 to berocked in its cradle and clamped inany position ofadjustment; andanother set screw 35 passing through a slot 31 in the member 35- isscrewthreaded into the member 32'.

The workpiece is shown at 33 and a quickrelease device for holding theworkpiece in position is constructed as follows: A lever 39 is pivotedbetween lugs 30 about a pivot pin 40. Screwthreaded into and passingthrough one end of the lever 39 is an adjustable locking screw 4| andengaging with the opposite endof the lever is a toggle lever 42' pivotedon a pin 43 mounted between lugs 44 extending upwardly from the bracketI29. In the position shownin Figure 4 the toggle lever 43 has been moveddownwardly by pressure on a finger-piece 45 so as to force the left-handend of lever 39 upwardly and thereby to depress the locking screw 4-!into firm contact with the workpiece 38= to hold it on the upper member33 of the workholder. Previously to clamping the workpiece in positionthe lower member 32 of th work-holder has beenadjusted in cradle 3| toany desired position of angular adjustment. In Figure the quick-releasedevice is shown in its released position for removal ofthe workpiece.

Mounted in the table I2 is a block 46 carrying a vertical cylindricalguide 41, the axis of which is tangential to the periphery or thegrinding wheel and is situated in a position to be engaged by theprofile of the master pattern.

It will be seen that in the construction described the carriage l3- canbe manipulated by hand, as in the case of any copying machine tool ofthis type, to maintain the profile of the master pattern in engagementwith the fixed guide 41 and by so doing the workpiece. 38 clamped inposition: above the master pattern will be ground to receive afinished'profile which is an exact copy of that of the master pattern.

By'adjusting the work-holder in cradl 31' the edge of the profile of theworkpiece cam be r'elieved, the degree of relief being dependentup'onthe angular adjustment of the work-holderin the cradle. The latter bearson its end surface graduated markings to which a fixed pointer on thecorresponding end of the member 32 can be set.

The lower slide rest I1, 20, 24 for carrying the master pattern enablesan initial adjustment of the position of the master pattern to be madein its setting in the carriage l3.

The carriage may, instead of being mounted for manual movement, becombined with any means by which it may be mechanically or otherwisemoved as may be found. most convenient.

Th work-holder can also be adjusted about the axis of the cross member21 for which purpose one end of the cross member extending through theleft-hand bearing shown in Figure 3 is screwthreaded as at 56 and alocking wheel 51 engages with the screwthread 56, a pressure washer 58being interposed between the boss of the locking wheel 51 and the outerextremity of bearing 28. The latter is conically formed to engage with aconical recess in the pressure washer. Thus, by loosening locking wheel51 the cross member 2-! can be angularly adjusted to its desiredposition and the degree of adjustment will be indicated by graduatedmarkings formed on the outer surface of the washer 58 as shown in Figur1-, and these markings can be set against a fixed pointer 59 attached tobracket 26. The washer 58 is caused to turn with the cross member 21 andfor this purpose is keyed at 60 to the cross member 21. Thus, to adjustth angular position of cross member 21 the locking wheel 57 will firstbe loosened, the cross member 21 and the parts it carries will then beadjusted with reference to th fixed pointer 59 after which the lockingwheel 51' will again be tightened and the parts will be held firmly intheir position of adjustment.

In order to true the grinding wheels from time to time the deviceillustrated in Figures 6 to 8 is conveniently employed.

Th truing device proper comprises a bracket as mounted to rotate onfixed guide 41, the parts being carefully machined so that as littleplay as possible exists in the mounting. Fixed to and extending upwardlyfrom bracket 48 is a standard 49 having a head 5!! in which is secured adiamond cutter 51-. The latter is conveniently carried at the end of amicrometer screw 5'2 passing completely through the head from. front toback and held in an adjusted position by means of a set screw 53. Ahandle 54 is screw-threaded into bracket 43 to afford means for swingingthe bracket: about the fixed guide 47. It will be appreciated that ifthe cutting point of the diamond Si is set in vertical alignment withthe outer surface of fixed guide 41 and the bracket 38- is swung: fromside to side about the axis of th guide W, the edge of the grindingwheel will be true to a curvature conforming exactly with the curvatureof the guide 41'. As is well known, the grinding wheel may be so mountedthat it can be fedtowards the truing tool for truing purposes.

In order to set the position ofthe diamond the bracket 48- can" bepassed over another rod 55 set apart from the machine and having thesame diameter as that of the fixed guide 41.

The height of rod 55, however, will be sufiicient toextend upwardlybeyond the point of the diamond cutterso that the latter can be broughtinto contact with the surface of rod 55; whereupon the set screw 53willbe tightened to hold the diamond in the position thus set.

This will ensure that when the bracket 48 is transferred on to fixedguide 41 the vertical alignment of the diamond cutter and the outersurface of guide 4'! will b ensured.

What is claimed is:

1. A grinding machine comprising in combination a rotatable grindingwheel and a carriage, means mounting said carriage for movement in anydirection parallel to and at a fixed distance from an imaginary planeparallel to the grinding wheel axis, a support on the carriage forattaching a master pattern thereto out of the plane of the axis, asupport on the carriage for holding a blank to be ground in a positionfor presentation to the grinding Wheel in line with the master patternin a direction normal to said imaginary plane and in the plane of saidaxis, and a stationary guide positioned -to engage the profile of themaster pattern, in

lin with the grinding wheel periphery in a direction normal to saidplane, whereby movement of the carriage parallel to the said plane willcause the pattern to traverse the guide and cause the grinding wheel toreproduce the pattern on the blank.

2. A grinding machine as claimed in claim 1 in which the support forattaching the master pattern to the carriage comprises crossed slides onthe carriage and means to individually adjust said slides so that themaster pattern may readily be positioned to any desired relationshipwith the means for holding the blanks.

3. A grinding machine as claimed in claim 1 in which the support forholding the blank includes means adjustable in relation to the carriageabout two axes at right angles to each other, one of said axes being atright angles to the axis of the grinding wheel when the carriag is inits normal relation to the wheel.

4. A grinding machine as claimed in claim 1 wherein the support forholding-the blank is mounted on a shaft, means rotatably supporting theshaft from the carriage with its axis parallel to the plane of referenceof the carriage-movement, and parallel to the grinding wheel spindle.

5. A grinding machine as claimed in claim 1, including a quick-releasedevice associated with the support for holding the blank thereon for thepurpose of clamping and releasing the same as desired.

6. A grinding machine as claimed in claim 1, wherein the mounting meansfor the carriage is a flat supporting plate, whereby universal movementthereof is eifected by moving the carriage over the plate.

7. A grinding machine as claimed in claim 1, wherein the supportingmeans for the carriage is a fiat plate, and antifriction bearing membersinterposed between the supporting plate and the carriage.

8. A grinding machine as claimed in claim 1, wherein the supportingmeans for th carriage is a flat plate, and ring ball bearings interposedbetween the carriage and the supporting plate.

9. A grinding machine as claimed in claim 1 in which the support for theblank comprises a cylindrical cradle mounted on said carriage and acorresponding cylindrical Work-holder adjustable therein, rthe axis ofthe cylinder being normally disposed at right angles to the axis of thegrinding wheel, for the purpose described.

10. A grinding machine comprising in combination a grinding wheelrotatable about a fixed axis, a fixed flat supporting plate having anupper surface parallel with the axis of the grinding wheel, a carriagemounted on the supporting plate for movement in any direction over thesurface thereof, means on the carriage for adjustably supporting amaster pattern, a guide having a guiding surface positioned so as to becapable of engagement with the master pattern and extending in adirection at right angles to the supporting plate and tangential to theedge of the grinding wheel, a cradle upon the carriage includingclamping means for a blank to hold the same for grinding by said wheeland means adjustable to cant the blank, one of said means beingadjustable about an axis parallel to the supporting plate and the otherabout an axis at right angles to the wheel axis so as to present theblank to the grinding wheel at any desired inclination while keeping themaster pattern engaged with the stationary guide.

11. A grinding machine as claimed in claim 10 including a quick-releasedevice associated with the cradle for holding the blank thereon for thepurpose of clamping and releasing the same as desired.

12. A grinding machine as claimed in claim 10, including anti-frictionmembers inserted between the supporting plate and the carriage.

13-. A grinding machine as claimed in claim 10, including ring ballbearings inserted between the supporting plate and the carriage.

MILDRED ANN SPURLING, Administratria: of the Estate of Bertram CharlesSpmling, Deceased.

